John O'Hart

A committed Roman Catholic and Irish nationalist, O'Hart had originally planned to become a priest but instead spent two years as a police officer.

O'Hart's 800-page, The Irish and Anglo-Irish landed gentry (Dublin 1884), was reprinted in 1969, with an introduction by Edward MacLysaght, the first Chief Herald of Ireland.

[citation needed] To complete his genealogies he used the writings of Cú Choigcríche Ó Cléirigh, Dubhaltach Mac Fhirbhisigh and O'Farrell, along with the Annals of the Four Masters, for the medieval pedigrees.

[citation needed] It is from the four other invaders — Heber, Ir, Heremon, and Ithe — from whom the Irish are alleged to descend.

Conn of the Hundred Battles was a descendant of Erimon, and Brian Boru was descended from both Heber and Conn.[citation needed] Irish pedigrees; or, The origin and stem of the Irish nation (1892), by John O'Hart, is available in 2 volumes free on the Internet Archive.